US2092342A - Metal feeder - Google Patents

Description

p 7, 1937- J. A. WALKER 2,092,342

METAL FEEDER Filed March 25, 1936 2 Sheets-Shem 1 J. A. WALKER METAL FEEDER 2 Sheets-Sheet 2 Filed March 25, 1936 -M, a l 0 Z n! 3 f5 3 H h r 7 m MW M V 5 J 4 w w 8 a 4 0 I /O 22 Slim/mug Patented Sept. 7, 1937 UNITED STATES PATENT oFFlcE Application March 25,

2 Claims,

This invention relates to improvements in metal feeders of the type shown in my prior Patent No. 1,978,775, dated October 30, 1934, for use in connection with line-casting, typesetting or strip machines, and has for its primary object to provide novel and improved means whereby metal pigs may be automatically fed to the metal pot in such manner that the molten metal in the pot will be maintained at a uniform level and even temperature-thus ensuring a marked economy in' gas or electricity and a higher quality of slugs.

The machine of the present invention contemplates the use of feeding mechanism, adapted to feed one or more metal pigs into the molten metal in the pot in an even manner, thus permitting the metal to melt gradually but at the proper rate for use, the feeding being smooth andfree from jerky movements.

A further object of the invention is to provide a structure which ensures safety in its feeding action since it cannot slip or 'overfeed the pot, and since it will keep the metal at a constant level for large as well as small slugs with a marked saving of time to the operator.

Another and important object of the invention is to provide a machine which is of great'simplicity, comprising few and simple parts of a character adapted to be readily assembled or disassembled, and which is readilyadjustable to proper position above metal pots of various typesetting or slug-casting machines.

Other and'important objects of the invention will be apparent during the course of the following description and by reference to the accom; panying drawings, in which:-

Fig. 1 is a side elevation of a metal feeder con structed in accordance with the invention.

Fig. 2 is an enlarged central vertical section of the feed and controlling means.

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2. i

Fig. 4 is a section taken on line 4-4 of Fig. 2. Fig. 5 is a section taken on line 5-5 of Fig.2. Fig, 6 is a section taken on line 6-45 of Fig. 2. Fig. 7 is a perspective view of one of the nut sections.

Fig. 8 is a view showing a feature of. construction.

Referring now more particularly to the draw-' ings, the numeral l0 designates a preferablycylin drical metallic housing open. at its upper end and normally closed by a head i I, secured thereto by bolts or like fastening means. The lower end I2of the housing and head I! are providedwith' 1936, Serial No. 70,837

centrally disposed alined openings l3. Formed in the side walls of the housing are suitable openings l4 and M in alinement with brackets l5 and I5 formed on or secured to the housing, on which brackets are respectively mounted a sheave i6 and a pivoted dog or pawl ll, for a purpose to be described. A bracket arm i8 is carried by a bracket member l9 adjustably mounted on a support 20, and the outer or free end of this bracket arm is provided with a forked portion 2i embracing and suitably connected with the upper end of the housing in. By means of this supporting arrangement, thehousing it) may be properly disposed with relation to a casting machine and adjustable to varying positions to accommodate it to casting machines of various forms.

Thenumeral 22 designates a feed screw, as a whole, having a relatively long threaded por tion 23 and a reduced smooth-upper portion 24, said reduced portion terminating in a stop shoulder 25 for engagement with feed mechanism, to be described, and serves to limit the downward movement of the screw. The screw 22 passes through the housing H3 and'openings l3 and is provided witha groove 26 for receiving a key rib 21 formed or provided upon the wall of the lower opening 13, whereby the screw 22 may partake of vertical movement with respect to the housing II], but cannot turn therein.

Means are provided to feed the screw in a vertical manner; comprising a cylindrical member 28, open at its upper end and normally closed by a head 29, rigidly secured thereto by screws or like fastening means. The head 29 is provided with a centrally arranged tubular spindle 30. The member 23 is rotatably mounted within the housing l0, and engages at its base suitable antifriction bearing means 3! disposed between it and the base of the housing. The member 28 is provided with a centrally disposed, downwardly tapering bore or chamber 32 of frusto-pyramidal or other suitable form, provided in two of its diametrically opposite fiat side walls with dovetailed grooves 33. Openings 3d and 34', corresponding in diameter to the opening B3 in the housing, and in alinement therewith, are formed respectively in the bottom'wall of the member 28 and in the head 29, for the passage of the screw. Mounted within the bore or chamber 32, is atwo-part feed nut 35 having dovetailed lugs or projections 36 on two of its diametrically opposite walls for engagement with the grooves 33. As clearly shown, the nut is of frusto-pyramidal form corresponding to the taper of the chamber 32. The two halves of the nut 35 are jointly provided with a screw threaded bore 3! of a diameter and pitch corresponding to the threads of the screw 22. It will be understood, of course, that the chamber 32 and nut 35 may be of circular instead of angular form, but the frusto-pyramidal form shown allows certain advantages in point of easier machining and other like Work, securing greater ease and convenience in the production of these parts.

Means are provided to rotate the member 28 and nut 35, said means being of clutch type for a step by step feed action, and comprising a ratchet sleeve or wheel 38 mounted upon the spindle 30, the teeth 39 of which ratchet wheel are engaged by the dog H, which controls the ratchet stroke. The ratchet wheel is provided with an upstanding hub 46 stably mounting it on the spindle 30. To this hub 40 is attached a chain or cable 4|, and to the dog or pawl I1 is attached a chain or cable 42 movable through an apertured guide lug 42' on the bracket l5, the chain or cable 4| being wound around the hub 40 for unwinding movement to transmit rotary motion in a screw feeding direction to the ratchet wheel. A coiled spring 43 is disposed about the hub 40 and has one of its ends fastened thereto and its opposite end engaged with a stud or projection 44 on the head H, and this spring acts, in opposition to the cable 4|, as a return spring for rotating the ratchet wheel in a reverse direction to that imparted to it by the cable 4|, when such motion is permitted by the dog or pawl IT, to set said ratchet wheel for a feed rotation of greater or less extent, or, in other words, to control the degree of feed movement of the ratchet wheel. The chains or cables 4| and 42 pass outwardly through the openings I4 and I4 in the housing and through the apertured lug 42, respectively, over the sheave i6 and are operatively connected to working parts to control the motions of the feeder, as hereinafter described. Head H is secured to the housing by bolts or screws passing through slots or openings in the head, allowing a limited rotation of the head to regulate the tension of the spring 43.

The screw 22 carries at its lower end a suspension hook 45 for suspending therefrom one or more metal pigs 46 in such position as to be accurately fed into the metal pot 41. The hook 45 is pivotally mounted on a sleeve or carrier fitting 43 secured to the screw and is provided with a hand lever 49 whereby it may be swung to a releasing position for dropping the remaining eye of a pig into the molten metal when desired.

The chain or cable 42 may include therein suitable means for adjusting it, or regulating its effective length, and is connected to a float 50 that extends into the pot 4'! and normally rests upon the molten metal therein. The position of this float, therefore, varies with the level of the molten metal in the pot, and the position of this float governs the action of the dog I! and the return movement of the ratchet wheel by the spring 43 to regulate the extent of feed motion of said ratchet wheel. Dog I! is mounted on a shaft journaled in spaced lugs Ila on the bracket l5. A spring 5|, coiled about the shaft has one end bearing on one of the lugs and its other end engaging a notch in the dog. This spring, acting on the dog, serves to take up slack in the chain or cable 42 and to normally hold the dog pressed against the teeth of the ratchet wheel.

The chain or cable 4| engages the outer end of a stroke adjusting arm 52, pivoted at 53 to the housing It and provided with a plurality of apertures 54. A chain or cable 55 engages any one of the apertures at its upper end and is suitably attached at its lower end to the back arm of the metal pot or some other movable part of a line casting machine, from which it will be seen that motion transmitted to the chain or cable 55 will be transmitted to the arm 52 and cable 4|. The chain or cable 55 may be provided with any suitable type of pot engaging and adjusting or slack take up means.

A coiled spring 56 is enclosed in an enlarged bore in the base of ratchet wheel 38. One end 55 of this spring is inserted in a hole in the base of the ratchet wheel, or secured thereto in some other manner, and the other end of the spring is free. This spring snugly surrounds the spindle 30 of the head 29. When the cable 4| is thrown outwardly, this spring acts as a clutch by gripping the spindle 30 of head 29 and brings the feeding mechanism into action. When the band spring 43 attached to the top of hood 40 of the ratchet wheel 38 returns the clutch, however, the spring 56 expands, or does not tighten, and has no gripping action whatever on the spindle, and

merely returns the ratchet wheel 38 in position for a second stroke.

In use, the device is mounted adjacent the casting machine in a position over the metal pot. The float 50 is connected with the chain or cable 42 and disposed to rest upon the molten metal, and

the cable or chain 55 is connected with the back arm of the metal pot. The device is then adjusted vertically to take up slack in the cables. Screw 22 is then forced upwardly by hand until raised to its highest working position. In this case the nut 35 will disengage the threads of the screw 22 when forced upwardly, due to its dovetailed engagement with the walls of the chamber 28, and immediately upon cessation of the raising movement of the screw will drop back and engage the screw, whereby the parts are initially set for feed action. One or more metal pigs 45 are then suspended from the hook 45 with the; lowermost end thereof just entering the molten casting position, metal in the pot the teeth 39 of the ratchet wheel 36, allowing the spring 43 to rotate backwardly or in a direction opposite to its feeding direction, to a greater or less degree. The chain or cable 4| will thus be wound up to a corresponding degree on the hub 40. Thus, when the melting pot is returned to its normal position, it pulls through the intervening connecting means upon the chain or cable 4| to rotate the ratchet sleeve 38 for a feed movement to the extent to which it has been adjusted by the spring 43, for regulating the extent of feed movement of the screw 22 accordingly. The ratchet wheel when rotating in feeding direction turns the member 28, and through it the nut 35, and the nut operates to feed the screw 22 downwardly to the extent necessary to supply the proper amount of metal to the pot. If, at any time, the amount of metal should fall below the prescribed level, the float in dropping down will disengage the pawl from the ratchet wheel to allow said wheel to turn backward the required distance for a subsequent feed action to supply the exact amount of new metal required to the pot. More particularly the action of the working parts is as follows: When metal pot r level, the float 50. acting as a weight on the chain or cable 42 willpull the pawl or dog i1 out of engagement with ratchet, the spring 56 gripping sleeve 36! and causing nut housing and nut to revolve, thus lowering feed screw. At the same time the spring 43 has wound up.

When metal pot goes forward from normal position the drive chain slackens,allowing the spring 43 to return the ratchet a distance dependent on engagement of pawl l7 withratchet. In this forward movement of pot, however, the spring 56 is free and does not grip the sleeve 38. If the molten metal in pot is low the ratchet will make its full return; if the metal is near its predetermined height the ratchet may only return a toothor two, leaving the drive chain slack.

Then when metal pot again returns to normal position, the drive chain can only feed the dis tance it had fallen back.

Whenever the metal pot is moved to its casting position, at a time whenthe metal is below its predetermined height, the spring 43 will unwind to the full extent allowed by the drive chain ll, the pawl H at this time being clear of the teeth of the ratchet wheel 39, owing to the weight of the float being greater than the tension of the spring 5|.

On the return of the pot to normal position, the drive chain 4| again winds up the spring 43. The drive chain 4| always holds against the tension of the spring 43 when the metal pot has fallen back to normal position. In other words, although the pawl I! may be in engagement between the ratchet teeth at this time, the pawl is free and is not the means which is holding against the ratchet wheel,

Whenever the metal pot is moved to its casting position and at about the time the metal in the pot has raised suliiciently to allow the pawl ii to fall back against the ratchet teeth, at any time in this movement the pawl ll may fall back into one of the teeth, and said pawl pulled'back against the side wall of opening i l by means of the spring 43. So in this case the pawl ll, pressed against the wall of opening M, in reality holds the spring 43 from unwinding further after the metal has reached its predetermined height.

However, as previously explained, the tension of the spring 43 is always held by the drive chain 4| and never by the pawl I? when the metal pot has completed its full return movement to normal position. The pawl ll, of course, is shaped to ride the teeth smoothly, there being a space of inch or more between the teeth. When the feeding action is stopped by means of the pawl engaging one of the ratchet teeth, the spring 43 will cause that tooth of the ratchet to pull back the pawl against the side wall M of the housing and in taking up this play the float will be raised to an almost unnoticeable degree off the surface of the metal. When feeding commences again on the return of the metal pot to normal position, the slack in the drive chain is first taken up, and it feeds for the balance of the stroke. It is on the forward movement of metal pot that the pawl engagement always occurs, and may occur in any one of the teeth. It is always on the return of the metal pot that the feeding of metal occurs after the slack of drive chain has been taken up. Thus the pawl l1 cannot become locked in a tooth of the ratchet. It will thus be seen that in the operation of the device the means connecting the ratchet wheel with the pot will turn said wheel in feeding direction, that the spring 43 moves, the ratchet 'wheel backward the extent required for a feed action dependent on the amount of metal in the pot, and that this return motion of the ratchet wheel by the, spring 43 is governed by the control dog and float, which releases the ratchet wheel for backward movement when the molten metal falls below the predetermined level in the pot, but holds it from such movement at all other times. The intermittent feeding action continues until the screw fi has been fed downward to a point where the upper smooth part 24 is engaged by the nut 35, at which time the stop shoulder 25 will support the weight of the screw. The weight of the metal suspended on the hook 45 will at all times keep the nut in flrm feedin engagement with the screw.

It is to be noted that when the molten metal in the pot is low, the dog I! will be pulled free of the ratchet teeth and the ratchet allowed to make its full stroke, but as the level of the molten metal in the pot rises the return strokes will gradually become shorter until the predetermined height of metal is reached, at which time the return stroke will completely cease. The float and connections therefore determine the length of stroke forward as well as return. When the feeding operation has ceased and the metal pot moves forward to casting position, the stroke adjusting arm 52 remains at its low point and the chain 55 becomes slack. Included in the length of this chain may be a safety spring connection 55' which elongates and comes into action only if part of the mechanism in the hous- This spring normally has no function in the regular operation of the apparatus beyond through slight movements preventing jerky actions in the drive chain 4 I,

It will be apparent, from the foregoing, that an extremely simple and highly efficient mechanism has been provided for feeding metal to metal pots of casting machines. The mounting of the device permits a convenient and accurate adjustment of the float, drive chain and proper positioning over the metal pot. The automatic feed results in a great saving of time to the operator and insures a constant level of the metal. The device further is constructed in such manner that it can be assembled or disassembled in a minimum of'time. The resetting of the feed screw requires but a fraction of a minute, since it is only necessary to force the screw upwardly.

It is understood that the invention is not limited to the precise construction shown, but that it includes within its purview whatever changes fairly come within either the terms or the spirit of the appended claims.

What I claim is:--

l. A metal feeder of the character described for use in type-casting machines, comprising a housing, a feed screw slidable through said housing, rotary means for imparting sliding movement to said screw, a clutch for controlling said rotary means, a connection between said clutch and the melting pot for imparting rotation thereto, a spring for returning said clutch, a float constantly resting on the surface of the molten metal at all times and coacting with said spring for controlling the degree of movement of said clutch, and a supporting means carried by the screw for suspending a metal pig in the melting pot, whereby the position of the float varies with the level of the molten metal in the pct.

able in said housing, means carried by the housing for preventing rotation of the screw, rotary means carried within the housing for imparting feeding movement to the screw, a ratchet toothed element for imparting movement to said rotary means, said element having means for connection with a melting pot for rotating said element 10 in screw feeding direction, a spring acting to rotate said element in the opposite direction to regulate its subsequent degree of rotation in feeding direction, a dog controlling the movement of the ratchet element under action of the spring, and a float for regulating the action of the dog constantly resting on the surface of the molten metal at all times, whereby the position of the float varies with the level of the molten metal in the pot.

JOSEPH AUTY WALKER.

Images